CD74HC173E

Overview

The CD74HC173E is a high-speed CMOS logic device manufactured by Texas Instruments, housed in a 16-pin PDIP package. It functions as a 4-bit parallel-load register utilizing four edge-triggered D-type flip-flops with true outputs. The component operates within a supply voltage range of 2V to 6V and supports a maximum clock frequency of 60MHz. It features an asynchronous active-high master reset input for immediate clearing of all stages. The device provides three-state outputs controlled by dual enable inputs, allowing it to drive up to 15 LSTTL loads while maintaining low power consumption typical of HC-CMOS technology.

Feature Summary

• Four edge-triggered D-type flip-flops provide synchronous data storage capability
• Parallel load architecture allows simultaneous data entry across all bits
• Asynchronous master reset ensures immediate clearing of stored states
• Three-state outputs facilitate direct connection to system buses

Applications

• High-speed disk and tape controller data buffering
• Communication interface signal buffering and routing
• General-purpose temporary data storage in digital systems
• Synchronous state holding in microprocessor-based circuits

Procurement Notes

Verify the specific suffix 'E' corresponds to the PDIP-16 through-hole package variant when sourcing. Confirm that the manufacturer is Texas Instruments, as other vendors produce equivalent 74HC173 devices with potentially different pinout or electrical characteristics. Ensure the procurement channel supplies genuine components to avoid counterfeit parts affecting timing performance.

Selection Notes

Select this component when a 4-bit register with parallel load functionality is required. The HC series offers wide voltage operation suitable for mixed-voltage environments. Consider the PDIP package only if through-hole assembly is mandated; otherwise, evaluate surface-mount alternatives like the PW or M variants for automated manufacturing processes.

Part Context

This device belongs to the 74HC (High-speed CMOS) logic family, designed for compatibility with standard TTL logic levels while offering improved speed and lower power dissipation compared to older NMOS technologies. The 74HC173 series is widely utilized in industrial and consumer electronics requiring reliable synchronous data handling.

FAQ

How is the data loaded into the register?

Data is loaded in parallel when both data enable inputs are held at a low logic level, capturing the input states on the rising edge of the clock signal.

What controls the output state?

The outputs are controlled by two enable inputs; they remain active when both enables are low and enter a high-impedance state if either enable goes high.